The clocks of the ancient Greeks

Vertical sundial οf north-western orientation

A vertical net orientated to the North-west with 5 engraved hour lines and 3 curves indicates, with the help of the shadow trace from the horizontal (vertical to the net) gnomon tip, 4 unequal (depending on the season) daily hours before the sunset (9th, 10th, 11th and 12th). The horizontal hour line at the height of the gnomon indicates the sunset. The left higher curve indicates the course of the sun's shadow at the winter solstice, the right at the summer solstice and the middle straight line at the equinoxes.